NCERT Class XI Mathematics - Permutations and Combinations - Solutions
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Question : 26
Total: 41
Find the number of ways of selecting 9 balls from 6 red balls, 5 white balls and 5 blue balls if each selection consists of 3 balls of each colour.
Solution:
No. of ways of selecting 3 red balls =
C 3
No. of ways of selecting 3 white balls =
C 3
No. of ways of selecting 3 blue balls =
C 3
∴ Required no. of ways of selecting 9 balls
=
C 3
C 3
C 3
×
×
×
×
No. of ways of selecting 3 white balls =
No. of ways of selecting 3 blue balls =
∴ Required no. of ways of selecting 9 balls
=
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